Balehaus at Bath, Bath, United Kingdom

Straw house passes fire safety tests

The publicity photo (who's that girl?) is misleading: the bale shown is obviously not the finished product. The house is a modern version of half-timbered tudoresque and very elegant.
Questions are: is the straw treated with fire resistant or cementitious material? is it compressed, if so how thick are the panels? are the timber framed panels non-structural? how do they retain their strength - is there framing inside the panels? What would happen if an owner drilled through the render to fix shelves etc. Would this affect the f/r? Or if the external render was damaged would water get in and soak the straw and degrade it?
Is there any comparison between the sustainability and cost between this and autoclaved aerated concrete blocks?
The big question is: can this product be made and used in third world countries? Is it possible for this panel to be made using their own natural materials e.g. rice straw and basic equipment or does it require sophisticated production methods? When I worked in the tropics we were always searching for building materials made of processed vegetable matter. 'Bagasse' made of compressed sugar cane thrash was an example, but the problem was the termites would get in and eat it. This is a very interesting product and we hope to follow the progress of it but I guess this is outside the scope of WAN. Couldn't find the fire test report on BRE, though

Research shows straw panels are 4 times safer than necessary

Newly engineered pre-fabricated panels made with straw have surpassed fire safety expectations by surviving for over two hours in temperatures over 1000°C. Researchers at the University of Bath used the panels in the construction of a prefabricated house, Balehaus at Bath, which is unveiled today.

The design is part of a major new research project into how these renewable building materials can be used for homes of the future. The panels used in Balehaus at Bath were constructed of a structural timber frame infilled with straw bales or hemp and rendered with a breathable lime-based system. The panels passed fire safety standards lasting four times as long as was required. The house will now be monitored over the next year by researchers from the University’s BRE Centre in Innovative Construction Materials for its insulating properties, humidity levels, air tightness and sound insulation qualities to assess the performance of straw and hemp as building materials.

Professor Pete Walker, Director of the University’s BRE Centre in Innovative Construction Materials said: “Straw is an ideal environmentally-friendly building material because it is renewable and is a by-product of existing farming production.

“Whilst we’ve previously done tests on individual ModCell panels, this is the first time data have been collected from a complete house. We’re hoping this will lead to these renewable materials being used more widely in the building industry for housing in the UK. The crop used for the straw can be grown locally, and because it absorbs carbon dioxide as it grows, buildings made from it have a very low carbon footprint.”

The Modcell Balehaus system, which is expected to be able to reduce heating bills by up to 85%, and CO2 emissions by 60%, has been used before by architectural television presenter Kevin McCloud to build an eco-friendly house in just six days on his Grand Designs show. The system is the creation of White Design in Bristol and Integral Structural Design in Bath. The research work on BaleHaus has been funded by Carbon Connections and the Technology Strategy Board.